Instrument for checking tolerances of work-pieces



April 24, 1956 w. HAUG 2,743,328

INSTRUMENT FOR CHECKING TOLERANCES OF WORK-PIECES Filed July 17, 1951 2Sheets-Sheet l lmmnhr;

April 24, 1956 w. HAUG 2,743,328

INSTRUMENT FOR CHECKING TOLERANCES OF WORK-PIECES Filed July 17, 1951 2Sheets-Sheet 2 United States Patent INSTRUMENT FOR CHECKING TOLERANCESOF WORK-PIECES Wilhelm Hang, Mulhouse, France, assignor to Manufacirurede Machines du Haut Rhin, Mulhouse-Bourtzwiller,

rance Application July 17, 1951, Serial No. 237,240 Claims priority,application France January 10, 1951 4 Claims. (Cl. 200-61.41)

The present invention relates to a precision gauging instrument by meansof which it is possible not only to verify that the prescribedtolerances of a machined workpiece are maintained, but also todetermine, at the same time, Whether the gauged dimensions are withinone or another of a plurality of predetermined limits.

This instrument is employed in combination with means suitable forrendering visible the results of gauging, that is With a luminousindicator.

The necessity of producing great numbers of precision work-pieces withvery small tolerances has led to the setting up of classifications.Work-pieces are classified into a convenient number of small groupsestablished according to the precision required for a faultlessoperation of the pieces.

The electro-mechanical gauging instrument according to the presentinvention is intended to reduce the duration of the gauging operation.Besides doing away with clearances required by previous mechanicalgages, which gauges because of their rapid wear, have to be frequentlyrenovated, the instrument of the present invention permits of aconsiderable saving of time.

This gauging instrument is represented by way of example in theaccompanying drawings:

Figs. 1, 2, 3 show diagrammatically in elevational view various stagesof the working of the controlling arm of the instrument;

Fig. 4 shows the circuit arrangement of the instrument.

The controlling arm E, employed according to the present invention,distinguishes itself from the controlling arms heretofore known andoperating in analogous ways, by a leaf-spring F additionally mounted onthe controlling arm E which carries contacts G1 cooperating with fixedcontacts A, C; this leaf-spring F carries contacts G2 and is soconstructed that feeble pressures are sufiicient to move it away fromits vertical position of rest. As opposed contacts B, D for the contactsG2 of the leafspring, use is made of two further contact-screws arrangedin an appropriate way. This arrangement is operatively combined,according to the accompanying wiring diagram shown in Fig. 4, with aluminous contact indicator in such a Way that, as long as thecontrolling arm and the leaf-spring are in the mean position shown inFig. 1, the white lamp, placed in the middle of the luminous indicator,is lit up. For the sake of clarity, the lamp that lights up to indicateactual position is, surrounded with a thick line in Figs. 1, 2 and 3.

The contacts G1 of the controlling arm are replaced in Fig. 4 by aswitch triangle H1. This triangle is equilateral and is made ofconductive material. The increase, thus obtained, in the scope ofregulation is considerable and of importance for the compactness of theinstrument. The operations is as follows:

If, for example in the gauging of a given Work-piece, the controllingarm E is moved away from its mean position (Fig. 1), contact occursfirst between the contact G2 or H2 of leaf-spring F with thecorresponding 2 contact screw B (Fig. 2). Then and lever s swings to theleft. The corresponding lamp which is, for example, bichromatic (whiteand red) lights up whereas the central lamp (white) is extinguished (seealso Fig. 2). If the displacement of the controlling arm is greater, thecontact G1 or H1 comes into contact with the opposed contact A (Fig. 3).The relay R is energized and consequently the lever 2 swings to theleft. The corresponding monochromatic (for example: red) lamp lights up,whereas the bichromatic lamp is extinguished (Fig. 3). As the contactscrews (A, B, C, D in Fig. 4) have their ends adjusted to the desiredtolerance stages, both ignition and extinction of the lamps alway occurat the very instant when a limit of said stage is crossed.

Each lamp, therefore, corresponds to a stage or section of the totaltolerance, so that work-pieces, which correspond to the same color,belong to the same tolerance group.

What is claimed is:

1. In a gauging instrument, in combination, stationary supporting means;a movable rigid body being mounted to said stationary supporting meansfor movement dependent on the dimensions of an article to be gauged; aresilient strip-shaped member secured at one end thereof to said movablerigid body so as to be displaced by a movement of the same; a firstmovable contact fixedly secured to said movable rigid body; a secondmovable contact arranged at the other end of said resilient member; afirst stationary contact mounted on said stationary supporting means andbeing adapted to cooperate with said first movable contact, said firstmovable contact being normally arranged at a distance from said firststationary contact; and a second stationary contact electricallyinsulated from said first stationary contact and the relay S isenergized mounted on said stationary supporting means and being adaptedto cooperate with said second movable contact, said second movablecontact being arranged normally at a distance from said secondstationary contact being smaller than the distance between said firstmovable contact and said first stationary contact whereby at a smallmovement of said rigid body in one direction only said second movablecontact arranged at said other end of said resilient member and saidsecond stationary contact make contact with each other, said firststationary contact and said first movable contact secured to saidmovable rigid body being separated from each other, whereas at a greatermovement of said rigid body in said one direction both said first andsecond movable contacts make contact, respectively, with said first andsecond stationary contacts, said reslient member assuming a curved shapethereby.

2. In a gauging instrument, in combination, stationary supporting means;a movable rigid arm being pivoted to said stationary supporting meansfor rotation dependent on the dimensions of an article to be gauged; aresilient strip-shaped member secured at one end thereof to said movablerigid arm so as to be displaced by a rotation of the same about thepivot thereof; a first movable contact fixedly secured to said movablerigid arm; a second movable contact arranged at the other end of saidresilient strip-shaped member; a first stationary contact mounted onsaid stationary supporting means and bein" adapted to cooperate withsaid first movable contact, said first movable contact being normallyarranged at a distance from said first stationary contact; and a secondstationary contact electrically insulated from said first stationarycontact and mounted on said stationary supporting means and beingadapted to cooperate with said second movable contact, said secondmovable contact being arranged normally at a distance from said secondstationary contact being smaller than the distance between said firstmovable contact and said first stationary contact whereby at PatentedApr. 24, 1956- a small rotation ofsaid rigid arm about the pivot thereofin one direction only said second movable contact are ranged at saidother end of said resilient strip-shaped member and said secondstationary contact make with contactvwith each other, said firststationary contact and said first movable contact secured to saidmovable rigid arm being separated from each other, whereas at a large totation of said rigid arm about the pivot thereof in said one directionboth said first and second movable contacts makecontact, respectively,with said first and second stationary contacts, said resilientstrip-shaped member assuming a curved shape thereby.

3. In a gauging instrument, in combination, stationary supporting means;a movable rigid arm being pivoted to said stationary supporting meansfor rotation dependent on the dimensionsof an article to be gauged; aresilient strip-shaped member secured at one end .thereofto said movablerigidarm so as to be displaced by a rotation of the same about the pivotthereof; a first movable contact fixedly secured to said movable rigidarm; a second movable contact arranged at the other end of saidresilient strip-shaped member; a first stationary contact mounted onsaid stationary supporting means at one side of said first movablecontact and being normally arranged at a distance therefrom; a secondstationary contact electrically insulated from .said first stationarycontact and mounted .on said stationary supporting means at oneside ofsaid second movable contact and at the same side as said'firststationary contact,.said second movable contact being arranged normallyat a distance from said sec ond stationary contact being smaller thanthe distance between said first movable contact and said firststationary contact; .a third stationary contact mounted on saidstationary supporting means at the other side of said first movablecontact and being normally arranged at a distance therefrom; a fourthstationary contact'electn'cally insulated'from said third stationarycontact and mounted on said stationary supporting means at the otherside of said second movable contact and at the same side as said thirdstationary. contact,xsaid second movable contact being arranged normallyat a distance from said fourth stationary contact being smaller than thedistance between.

said first movable contact and said third stationarycontact whereby at asmall rotation of said arm about the pivot thereof in any direction saidsecond movable contact arranged on said other end of said resilientstripshaped member makes contact with one of said second and fourthstationary contacts, said first and third stationary contacts beingseparated, respectively, by distances from said first movable contact,whereas at a large rotation of said arm about the pivot thereof bothsaid first and second movable contacts make contact, respectively, withone of said first and third stationary contacts and one ofsaid secondand fourth stationary contacts, said resilient strip-shaped memberassuming a curved shape thereby.

4. Ina gauging instrument, in'combination, stationary supporting means;a movable rigid arm being pivoted to said stationary supporting meansfor rotation dependent on the dimensions of an article to be gauged; aresilient strip-shaped member secured at one end thereof to said movablerigid arm so as to be displaced by a rotation of the same about thepivot thereof; a first movable contact fixedly secured to said movablerigid arm and being shaped as a triangle having a base substantially atright angles'to said rigid arm and a vertex forming the end of saidrigid arm carrying said resilient strip-shaped member; a second movablecontact arranged at the other end of said resilient strip-shaped member;a first stationary contact mounted on said stationary supporting meansat one side of said first movable contact and being normally arranged ata distance therefrom; a second stationary contact electrically insulatedfrom said first stationary contact and mounted on said stationarysupporting means at one side of said second movable contact and at thesame side as said first stationary contact, said second movable contactbeing arranged normally at a distance from said second stationarycontact being smaller than the distance between said first movablecontact and said first stationary contact; a third stationary contactmounted on said stationary supporting means at the other side of saidfirst movable contact and being normally arranged at a distancetherefrom; a fourth stationary contact electrically insulated from saidthird stationary contact and mounted on said stationary supporting meansat the other side of said second movable contact and at the same side assaid third stationary contact, said second movable contact beingarranged normally at a distance from said fourth stationary contactbeing smaller than the distance between said first movable contact andsaid third stationary contact whereby at a small rotation of said armabout the pivot thereof in any direction said second movable contactarranged on said other end of said resilient strip-shaped member makescontact withone of said second and fourth stationary contacts, saidfirst and third stationary contacts being separated, respectively, bydistances from said first movable contact, whereas at a large rotationof said arm about the pivot thereof both said first and second movablecontacts make contact, respectively, with one of said first and thirdstationarycontacts and one of said second and fourth stationarycontacts, said resilient strip-shaped member assuming a curved shapethereby.

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